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Aftershock Forecast Sequence-Specific Model Parameters
AftershockForecastSequence-SpecificModelParameters.png
AftershockForecastSequence-SpecificModelParameters.png
AftershockForecastSequence-SpecificModelParameters.png

Aftershock Forecast Sequence-Specific Model Parameters equation 

The probability distribution for the number of aftershocks, P(N), and the forecast can then be computed using the same procedures as for the generic model, using Pseq-spec(a) instead of Pgeneric(a).

Aftershock Forecast Sequence-Specific Model Parameters equation 

The probability distribution for the number of aftershocks, P(N), and the forecast can then be computed using the same procedures as for the generic model, using Pseq-spec(a) instead of Pgeneric(a).

An example of Bayesian updating of productivity parameter (a-value) for the 2010 Mw 8.8 Maule, Chile, earthquake. Immediately following the earthquake, the SZ-GENERIC region-specific a-value distribution can be used. As the aftershock sequence progresses and additional data are collected, this distribution can be treated as a prior distribution and updated using Bayes’ rule. Posterior distributions at subsequent time intervals are shown. Figure from Page et al. (2016).
AftershockForecastfig6.gif
AftershockForecastfig6.gif
AftershockForecastfig6.gif

An example of Bayesian updating of productivity parameter (a-value) for the 2010 Mw 8.8 Maule, Chile, earthquake. Immediately following the earthquake, the SZ-GENERIC region-specific a-value distribution can be used.

An example of Bayesian updating of productivity parameter (a-value) for the 2010 Mw 8.8 Maule, Chile, earthquake. Immediately following the earthquake, the SZ-GENERIC region-specific a-value distribution can be used.

Screenshot of the Aftershock Forecast for an earthquake in California, showing the information box at the top of the forecast and the four tabs of forecast information.
Mendocino_headerinfo-2.jpg
Mendocino_headerinfo-2.jpg
Mendocino_headerinfo-2.jpg

Screenshot of the Aftershock Forecast for an earthquake in California, showing the information box at the top of the forecast and the four tabs of forecast information.

Screenshot of the Aftershock Forecast for an earthquake in California, showing the information box at the top of the forecast and the four tabs of forecast information.

Equation 2 for the Aftershock Forecast probability distribution to compute the forecast
AftershockEquation2Screenshot.png
AftershockEquation2Screenshot.png
AftershockEquation2Screenshot.png

Equation 2 for the Aftershock Forecast probability distribution to compute the forecast

Equation 2 for the Aftershock Forecast probability distribution to compute the forecast

A white plume of volcanic gas rises from a volcanic vent in a crater
March 14, 2025 — Kīlauea summit eruption overflight with Mauna Loa in the background
March 14, 2025 — Kīlauea summit eruption overflight with Mauna Loa in the background
March 14, 2025 — Kīlauea summit eruption overflight with Mauna Loa in the background

A low-angle aerial view of the vents where episodic fountaining has been occurring since the start of the ongoing Kīlauea summit eruption on December 23, 2024. A white plume of volcanic gas rises from the north vent (center right) and south vent (center left) cones in the southwest corner of Halema‘uma‘u crater, as viewed during a monitoring overflight.

A low-angle aerial view of the vents where episodic fountaining has been occurring since the start of the ongoing Kīlauea summit eruption on December 23, 2024. A white plume of volcanic gas rises from the north vent (center right) and south vent (center left) cones in the southwest corner of Halema‘uma‘u crater, as viewed during a monitoring overflight.

Icon for ShakeMap
ShakeMap icon
ShakeMap icon
ShakeMap icon

Icon used to refer to ShakeMap on Product landing pages. For example use, see https://staging-earthquake.usgs.gov/data/pager/background.php.

Icon used to refer to ShakeMap on Product landing pages. For example use, see https://staging-earthquake.usgs.gov/data/pager/background.php.

Two example aftershock sequences, from southern California, that illustrate the three general rules of aftershocks. A circle shows each aftershock's time of occurrence (horizontal axis) and magnitude (vertical axis). The larger-magnitude M6.7 Northridge earthquake is followed by many more aftershocks than the smaller M5.1 La Habra earthquake. The rate of aftershocks in both sequences decreases as time passes. The magnitudes of the aftershocks don't change with time, meaning that large aftershocks are still
fig4.gif
fig4.gif
fig4.gif

Two example aftershock sequences, from southern California, that illustrate the three general rules of aftershocks. A circle shows each aftershock's time of occurrence (horizontal axis) and magnitude (vertical axis). The larger-magnitude M6.7 Northridge earthquake is followed by many more aftershocks than the smaller M5.1 La Habra earthquake.

Two example aftershock sequences, from southern California, that illustrate the three general rules of aftershocks. A circle shows each aftershock's time of occurrence (horizontal axis) and magnitude (vertical axis). The larger-magnitude M6.7 Northridge earthquake is followed by many more aftershocks than the smaller M5.1 La Habra earthquake.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “M4+” and “Show All” selections for magnitude and forecast duration.
Mendocino_M4all.jpg
Mendocino_M4all.jpg
Mendocino_M4all.jpg

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “M4+” and “Show All” selections for magnitude and forecast duration.
 

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “M4+” and “Show All” selections for magnitude and forecast duration.
 

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “M4+” and “Show All” selections for magnitude and forecast duration.
Mendocino_M41month.jpg
Mendocino_M41month.jpg
Mendocino_M41month.jpg

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “M4+” and “Show All” selections for magnitude and forecast duration.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “M4+” and “Show All” selections for magnitude and forecast duration.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, scrolled to the bottom of the page. The mainshock is shown with a yellow star on top of its circle; other earthquakes in the forecasting region are also shown colored by time of occurrence.
Mendocino_map copy.jpg
Mendocino_map copy.jpg
Mendocino_map copy.jpg

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, scrolled to the bottom of the page. The mainshock is shown with a yellow star on top of its circle; other earthquakes in the forecasting region are also shown colored by time of occurrence.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, scrolled to the bottom of the page. The mainshock is shown with a yellow star on top of its circle; other earthquakes in the forecasting region are also shown colored by time of occurrence.

A screenshot of the Aftershock Forecast Model Parameters
Mendocino_parameters.jpg
Mendocino_parameters.jpg
Mendocino_parameters.jpg

Aftershock Forecast Model parameters screenshot of the Aftershock Forecast Overview page

Aftershock Forecast Model parameters screenshot of the Aftershock Forecast Overview page

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Forecast Table” tab selected.
Mendocino_table.jpg
Mendocino_table.jpg
Mendocino_table.jpg

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Forecast Table” tab selected.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Forecast Table” tab selected.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Commentary” tab selected.
Mendocino_table.jpg - Copy
Mendocino_table.jpg - Copy
Mendocino_table.jpg - Copy

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Commentary” tab selected.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Commentary” tab selected.

Screenshot of the Overview webpage for an earthquake in California. The “Aftershock Forecast” card is at lower center.
Aftershock Forecast on the earthquake event page
Aftershock Forecast on the earthquake event page
Aftershock Forecast on the earthquake event page

Screenshot of the Overview webpage for an earthquake in California. The “Aftershock Forecast” card is at lower center.

Screenshot of the Overview webpage for an earthquake in California. The “Aftershock Forecast” card is at lower center.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “Show All” and “1
Aftershock Forecast for an earthquake in California
Aftershock Forecast for an earthquake in California
Aftershock Forecast for an earthquake in California

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “Show All” and “1 Month” selections for magnitude and forecast duration.

Screenshot of the Aftershock Forecast for an earthquake in California, with the “Summary” tab selected, and “Show All” and “1 Month” selections for magnitude and forecast duration.

Venn Diagram of risk as the intersection of hazards and society.
Hazard Risk and Society Venn Diagram
Hazard Risk and Society Venn Diagram
Hazard Risk and Society Venn Diagram

Ven diagram of risk as the intersection of hazards and society. This illustrates the logical relationships between two or more sets of items. 

Ven diagram of risk as the intersection of hazards and society. This illustrates the logical relationships between two or more sets of items. 

woman smiling with gray jacket.
Tricia Light Staff Profile
Tricia Light Staff Profile
Tricia Light Staff Profile

Tricia Light works with the Natural Hazards Mission Area and has a background in marine chemistry.

Tricia Light works with the Natural Hazards Mission Area and has a background in marine chemistry.

View of Mount Adams from a distance, scientists installing a monitoring station, and map where earthquakes have occurred.
Update on seismic activity at Mount Adams from September 2024 to early November 2024
Update on seismic activity at Mount Adams from September 2024 to early November 2024
Update on seismic activity at Mount Adams from September 2024 to early November 2024

Volcanoes tend to have seismicity that waxes and wanes over time. That’s considered normal and not necessarily a cause for concern. Let’s check on Mount Adams to see what USGS scientists are doing to learn more about its recent earthquake activity and what it could mean for this Cascade Range volcano.

Volcanoes tend to have seismicity that waxes and wanes over time. That’s considered normal and not necessarily a cause for concern. Let’s check on Mount Adams to see what USGS scientists are doing to learn more about its recent earthquake activity and what it could mean for this Cascade Range volcano.

landslide safety infographic
Landslide Safety
Landslide Safety
Landslide Safety

LANDSLIDE SAFETY

If your home or property was damaged by a landslide from Hurricane Helene, be aware of the warning signs of future landslide activity

 

WATCH FOR WARNING SIGNS

Signs a landslide may be moving include:

LANDSLIDE SAFETY

If your home or property was damaged by a landslide from Hurricane Helene, be aware of the warning signs of future landslide activity

 

WATCH FOR WARNING SIGNS

Signs a landslide may be moving include:

4 photos of seismic instruments in a barren room
Seismographs at the Albuquerque Seismological Laboratory
Seismographs at the Albuquerque Seismological Laboratory
Seismographs at the Albuquerque Seismological Laboratory

(a) Photograph of instruments being tested in the East portion of the underground vault. (b) Wench and location of three boreholes in the West portion of the underground vault. (c) Cross-tunnel and recording equipment for the reference sensor vault.

(a) Photograph of instruments being tested in the East portion of the underground vault. (b) Wench and location of three boreholes in the West portion of the underground vault. (c) Cross-tunnel and recording equipment for the reference sensor vault.

aerial view of desert with a group of buildings and mountains in the background
Aerial View of the Albuquerque Seismological Laboratory
Aerial View of the Albuquerque Seismological Laboratory
Aerial View of the Albuquerque Seismological Laboratory

Arial view from the North of the Albuquerque Seismological Laboratory on the Kirtland Air Force Base about 15 miles southeast of Albuquerque, New Mexico.

Arial view from the North of the Albuquerque Seismological Laboratory on the Kirtland Air Force Base about 15 miles southeast of Albuquerque, New Mexico.

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